Clean cauliflower well and cut into florets. Place cauliflower florets in medium-size pot. Pour chicken stock over florets and boil over high heat for 8 minutes. While cauliflower is cooking, place kale in blender. Add half and half and blend until kale is well pulverized. Add cream cheese and blend well. Set aside. Once cauliflower is fork-tender, drain well and mash. Stir butter into mashed cauliflower. With a mixer, blend kale mixture into mashed cauliflower. Stir in Parmesan cheese, pepper, garlic salt, and apple cider vinegar. Serve warm.